The present invention is a rotor assembly of truncated cone discs designed for compatible use with a solids discharging means taught in U.S. Pat. No. 3,861,584, to Dudrey, for a "Self-Purging Centrifuge". The centrifuge in that patent is directed to the separation of a liquid from the solids suspended within the liquid. An effective purging process is taught in the patent whereby relatively small forces are used to wash the accumulated particles from the centrifuge drum wall. The particles become resuspended in the fluid and are then purged from the centrifuge system. Although proving to be highly effective for liquid/solid separations, the self-purging centrifuge of U.S. Pat. No. 3,861,584 cannot be operated as disclosed in the patent for liquid/liquid/solid separation.
There is a need in certain industries, e.g., metal working, for a centrifuge capable of separating a lighter liquid from a heavier liquid while simultaneously separating the suspended solid particles from both liquids, without necessitating the use of a pre-filter. Pre-filters are used in prior art centrifuges to remove larger size solid particles from a fluid prior to the application of centrifugal forces to the fluid. In addition to the use of pre-filters the centrifuges presently being used in the metal working industry normally operate at relatively high speeds of 6,000 to 20,000 rpm and as a result are subject to vibrational and unbalancing problems. Further, the prior art certrifuges have complicated "clam-shell opening" constructions and sensoring means for the disposal of accumulated solid particles from the centrifuge's interior. The self-purging method of the centrifuge in U.S. Pat. No. 3,861,584 allows a simpler design while maintaining high effectiveness in the removal of accumulated solids. The present invention, using the purging technique taught in U.S. Pat. No. 3,861,584, provides a self-purging centrifuge which effectively allows the simultaneous separation of a light liquid, a heavier liquid and suspended solids from the fluid introduced into the centrifuge. The simple design, the absence of a pre-filter, and reduced operational speeds without accompanying vibrational and imbalancing problems, all combine with the structure of the present invention to provide industry with a self-purging centrifuge meeting its heretofore unanswered need for an economical yet effective liquid/liquid/solid centrifuge.